Fired tank heater seal



Nov. 5, 1963 .1. J. REAGAN ETAL 3,109,423

FIRED TANK HEATER SEAL Filed June 28, 1962 INVENTOR.

JOHN J. REAGAN 8 BY MARVIN L. PAYNE OU MWM D W J 2 I ATTORNEYS UnitedStates Patent 3,109,423 FKRED TANK HEATER SEAL John J. Reagan and MarvinL. iayne, Parnla, Ohio, assignors to The Standard Oil Company,Cieveiand, Ohio, a corporation of Ohio Filed June 28, 1962, Ser. No.205,074 4 Claims. (til. ran-see This invention relates in general tofired tank heaters and more particularly to means :for sealing the idlefiretubes of the heater during periods when less than the total numberof burners are in operation.

The conventional fired tank heater used to maintain or raise thetemperature of the tank contents comprises a plurality of firetubes, gasburners individually associated therewith at corresponding open ends ofthe same, and a common exhaust stack. Regulation of the heat input tothe contents of the tank is provided by varying the number of burnersoperating or fired at a given time, and when less than all areoperative, which often occurs, heat is lost through the one or moreunused tubes. This heat loss occurs as a result of ambient air beingdrawn through the idle firetube or firetubes by the draft in the commonstack which will exist even when all burners are off and of course ismuch more pronounced when some of the burners are operative. Heat lostin this manner must normally be replaced by burning additional fuel.

it has, for example, been found by testing one such installation thatthe average temperature rise of ambient air drawn through idle firetubeswas on the order of 150 F., with the velocity of the air stream throughsuch tubes varying from 400 to 1400 feet per minute. This considerabletemperature rise is of course produced by extraction of heat from thetank contents and must be replaced as aforementioned.

"it is therefore a primary object of the invention to provide such afired tank heater equipped with sealing means for eliminating heatlosses resulting as discussed above in operation with one or more idlefiretubes.

The noted sealing means serve, moreover, to prevent dust and the likefrom entering the idle firetubes and to improve the draft conditions forany operating burner or burners in operation.

Another object is to provide firetube seals which are of simpleconstruction, inexpensive, and easy to apply to obtain varying desiredsealing conditions of the heater.

Other objects and advantages of the present invention will becomeapparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention,then, comprises the features hereinafter fully described andparticularly pointed out in the claims, the following description andthe annexed drawings setting forth in detail certain illustrativeembodiments of the invention, these being indicative, however, of but afew of the various ways in which the principle of the invention may beemployed.

In said annexed drawings:

FIG. 1 is a transverse sectional view taken on lines 11 of FIG. 2showing in simplified form a fired tank and heater provided withfiretube seals in accordance with the invention;

FIG. 2 is a fragmentary elevation of the tank in which the seals areshown in solid lines in an inoperative condition, and one of the sealsis shown in dotted lines in a particular sealing condition;

FIG. 3 is a side elevation, on an enlarged scale, of a burner andassociated 'firetube with the seal in interposed sealing position;

FIG. 4 is a perspective view of the PEGv 3 assembly and FIG. 5 is a topview of such FIG. 3 assembly.

3=,l09,423 Patented Nov. 5, 1963 Referring now to the drawings indetail, reference numeral 10 designates a cylindrical tank forcontaining material to be heated or maintained at an elevatedtemperature, such as, for example, molten asphalt. It will be understoodthat the tank itself may be of any suitable construction, with thedetails thereof not forming a part of the present improvements.

Several gas burners 12 are provided in spaced relation adjacent the sideof the tank, with these burners served by a common supply conduit 14from a source of the combustible mixture used. Each burner 12 may have asuitable control valve (not shown) whereby the flow of gas thereto canbe independently controlled, and shut off. Firetubes 16 extend in apreferably curved path through the tank E10, with each having having anopen end in close spaced relation to a gas burner and the opposite tubeends commonly communicating with an exhaust stack 18 vertically disposedexteriorly of the vessel to convey the combustion products to a removedpoint for appropriate disposition thereof. The ifiretubes 16 arepreferably curved better to accommodate expansion thereof duringheating.

The heater structure thus described is Well known; a simpleconfiguration has been shown and other configurations could as Well beemployed.

The new firetube seals are designated at '24 and are preferably madefrom an appropriately sized resilient steel sheet folded generally alongthe longitudinal centerline to provide a pair of leaf sections 22 and24, interconnected at the fold line 26. A chain 28 is preferably Weldedor otherwise connected at one end to each seal, the other end of eachchain being secured to the wall of the tank 10 by any suitable means,whereby the seals during periods of none-use hang conveniently adjacentthe burnerassernbly as shown in solid lines in FIG. 2. It will beobvious that the hanging of the seals as shown merely insures theavailability of the seals When needed and thus any suitable means can beprovided for such purpose.

When the operation of the heater calls for a burner to be shut off andthis is done, the end of the associated and now idle firetube is sealedby interposing the seal 20 associated therewith between this burner andthe firetube end as shown by Way of example in dotted lines in FIG. 2.As shown most clearly in FIGS. 3-5, diverging leaf sections 22 and 24 ofthe seal 20 respectively contact the opposed ends of the gas burner andassociated firetube, and the relative separation is such that theresilient leaf sections are forced inwardly against such opposed endsfor spring holding of the seal in place. Although in HS. 2 only a singleseal 2% is shown in sealed position, with the remaining firetubesremaining open and operative, it will be apparent that if desired allthree of the seals or other desired combinations of seals can be movedto seal ing positions.

It will be evident that the firetube seals are extremely simple and easyto use for eliminating the otherwise experienced heat losses discussedabove through idle tube draft. The burners are used to assist inoperative positioning of the seals, and no structural modification of anexisting heater installation on the order described is necessary torealize the very practical benefits afforded by the use of these seals.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided thefeatures stated in any of the followingclaims or the equivalent of suchbe employed.

We, therefore, particularly point out and distinctly claim as ourinvention:

1. In combination with a vessel; heater means therefor comprising atleast one gas burner at the exterior of the vessel, at least onefiretube extending through the vessel with an open end thereof in spacedopposition to said burner, and tube sealing means having leaf sectionsnormally separated more than the spacing of said firetube end from saidburner, said sealing means being insertable between said burner and tubeend upon forcing of said sections together and thus held by springcontact with the same, the section of the sealing means overlying theend of said firetu be being imperforate and closing such end againstadmittance of air.

2. The combination of claim 1 wherein said sealing means is a singiepiece of general V-shape.

3. In combination with a vessel; heater means therefor comprising aplurality of gas burners at the exterior of the vessel, firetubesassociated with said humers extending through the vessel, with the, openends thereof respectively in spaced opposition to said mirners, and acommon stack for said firetubes; and a plurality of firetube seals, 21single firetube seal adapted to be associated With each of said burnerand associated 'firetube, each of said firetube seals having resilientleaf sections normally separated more than the spacing of said firetubeends from the burners, said firetube seals being insertable between saidassociated burners and tube ends upon forcing of said sections togetherand thus held by spring contact with the same, each of said "firetubeseals being imperforate and closing the associated firetube end againstadmittance of air.

4. The combination of claim 3 wherein each of said firetube seals is asingle piece of general V-shape.

References Cited in the file of this patent UNITED STATES PATENTS866,943 Long Sept. 24, 1907 1,202,736 Kling et a1. Oct. 24, 19161,442,017 Watry Jan. 9, 1923 1,464,069 Gerber Aug. 7, 1923 1,567,131Flinn Dec. 29, 1925 1,626,301 Rhodes Apr. 26, 1927 1,751,533 Taylor Mar.25, 1930 1,821,726 Saporta Sept. 1, 1931 2,288,731 NeWlon July 7, 19423,060,922 \Wflson Oct. 30, 1962

1. IN COMBINATION WITH A VESSEL; HEATER MEANS THEREFOR COMPRISING ATLEAST ONE GAS BURNER AT THE EXTERIOR OF THE VESSEL, AT LEAST ONEFIRETUBE EXTENDING THROUGH THE VESSEL WITH AN OPEN END THEREOF IN SPACEDOPPOSITION TO SAID BURNER, AND TUBE SEALING MEANS HAVING LEAF SECTIONSNORMALLY SEPARATED MORE THAN THE SPACING OF SAID FIRETUBE END FROM SAIDBURNER AND TUBE END UPON FORCING OF SAID BETWEEN SAID BURNER AND TUBEEND UPON FORCING OF SAID SECTIONS TOGETHER AND THUS HELD BY SPRINGCONTACT WITH THE SAME, THE SECTION OF THE SEALING MEANS OVERLYING THEEND OF SAID FIRETUBE BEING IMPERFORATE AND CLOSING SUCH END AGAINSTADMITTANCE OF AIR.